[Script run 2019-04-16 14:54:48]
Sane responses fulfil all:
estimate (1890, 2010)
after <= estimate
before >= estimate
after >= 1800
before <= 2000
| Var1 | Freq |
|---|---|
| TRUE | 1553 |
| Estimate out of range | 0 |
| After out of range | 0 |
| Before out of range | 0 |
| After after estimate | 0 |
| Before before estimate | 0 |
## Warning: Column `id` joining character vector and factor, coercing into
## character vector
| id | questionCount | hitRate | bracketRate | goodAnswerRate | meanError | sdError | meanBracketWidth | sdBracketWidth | meanRT | hard_easy | dull_fun | tooLong_tooShort | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| c49507a0 | c49507a0 | 10.00 | 0.30 | 1.00 | 1.00 | 11.50 | 12.03 | 47.20 | 30.11 | 21881.70 | 0.50 | 0.50 | 0.50 |
| 42057dd2 | 42057dd2 | 50.00 | 0.84 | 0.96 | 1.00 | 0.94 | 3.59 | 18.14 | 6.66 | 46364.70 | 0.42 | 0.50 | 0.45 |
| c030ca6d | c030ca6d | 50.00 | 0.16 | 0.80 | 1.00 | 12.24 | 18.82 | 26.82 | 21.40 | 42456.60 | 0.18 | 0.74 | 0.50 |
| 0d739e63 | 0d739e63 | 50.00 | 0.16 | 0.78 | 1.00 | 9.20 | 16.49 | 13.42 | 11.22 | 38530.98 | 0.27 | 0.72 | 0.51 |
| 917ff8c7 | 917ff8c7 | 50.00 | 0.22 | 0.72 | 1.00 | 9.74 | 19.35 | 9.18 | 5.59 | 38148.84 | 0.31 | 0.70 | 0.37 |
| 6c343b84 | 6c343b84 | 50.00 | 0.08 | 0.64 | 1.00 | 14.46 | 16.51 | 30.74 | 24.58 | 17500.86 | 0.08 | 0.84 | 0.48 |
| b0f3567b | b0f3567b | 50.00 | 0.04 | 0.58 | 1.00 | 18.36 | 17.42 | 30.88 | 18.43 | 26714.30 | 0.39 | 0.43 | 0.33 |
| 5f3972fc | 5f3972fc | 50.00 | 0.02 | 0.58 | 1.00 | 20.04 | 17.28 | 35.10 | 19.12 | 19798.84 | 0.76 | 0.61 | 0.50 |
| dcd1e104 | dcd1e104 | 50.00 | 0.04 | 0.58 | 1.00 | 24.76 | 21.87 | 43.38 | 21.35 | 38001.68 | 0.00 | 0.00 | 0.00 |
| 8c8944b1 | 8c8944b1 | 50.00 | 0.06 | 0.58 | 1.00 | 12.32 | 14.54 | 21.10 | 18.45 | 20069.58 | 0.10 | 0.84 | 0.14 |
| c6ab2f87 | c6ab2f87 | 50.00 | 0.06 | 0.56 | 1.00 | 12.70 | 14.15 | 18.60 | 10.73 | 27507.32 | 0.14 | 0.90 | 0.35 |
| 37baec64 | 37baec64 | 50.00 | 0.08 | 0.54 | 1.00 | 15.14 | 17.95 | 15.86 | 10.48 | 15202.16 | 0.00 | 0.37 | 0.00 |
| cdd73ca9 | cdd73ca9 | 50.00 | 0.22 | 0.52 | 1.00 | 18.26 | 19.68 | 20.48 | 13.41 | 29056.02 | 0.00 | 0.27 | 0.46 |
| 509526f2 | 509526f2 | 50.00 | 0.06 | 0.50 | 1.00 | 27.20 | 23.96 | 38.44 | 22.41 | 29018.10 | 0.36 | 0.50 | 0.50 |
| cbfef2dd | cbfef2dd | 50.00 | 0.10 | 0.50 | 1.00 | 17.18 | 20.19 | 10.12 | 3.21 | 24107.60 | 0.30 | 0.92 | 0.53 |
| 5355b9da | 5355b9da | 50.00 | 0.18 | 0.48 | 1.00 | 18.98 | 19.20 | 19.04 | 9.87 | 22428.48 | 0.14 | 0.80 | 0.38 |
| 0662f6a6 | 0662f6a6 | 50.00 | 0.02 | 0.48 | 1.00 | 20.40 | 25.83 | 17.62 | 16.23 | 18512.42 | 0.00 | 0.48 | 0.35 |
| aed90615 | aed90615 | 50.00 | 0.02 | 0.46 | 1.00 | 19.58 | 16.80 | 29.38 | 15.04 | 19121.20 | 0.03 | 0.83 | 0.50 |
| 94950854 | 94950854 | 50.00 | 0.06 | 0.46 | 1.00 | 17.46 | 18.87 | 22.40 | 17.42 | 21570.20 | 0.17 | 0.88 | 0.52 |
| ae485d3e | ae485d3e | 46.00 | 0.02 | 0.46 | 1.00 | 17.83 | 15.99 | 28.07 | 16.89 | 27025.13 | 0.01 | 0.42 | 0.46 |
| 6d8bc8a8 | 6d8bc8a8 | 50.00 | 0.04 | 0.42 | 1.00 | 19.84 | 20.49 | 16.40 | 8.44 | 25511.06 | 0.00 | 1.00 | 0.51 |
| ede87ff3 | ede87ff3 | 50.00 | 0.02 | 0.40 | 1.00 | 16.74 | 18.80 | 14.54 | 7.74 | 39720.06 | 0.19 | 1.00 | 0.45 |
| ede87ff3 | ede87ff3 | 50.00 | 0.02 | 0.40 | 1.00 | 16.74 | 18.80 | 14.54 | 7.74 | 39720.06 | 0.19 | 1.00 | 0.45 |
| d16c6455 | d16c6455 | 50.00 | 0.02 | 0.38 | 1.00 | 27.16 | 22.55 | 27.42 | 21.90 | 32408.86 | 0.17 | 0.91 | 0.50 |
| d5d714de | d5d714de | 47.00 | 0.02 | 0.36 | 1.00 | 29.51 | 25.07 | 26.00 | 10.12 | 27858.09 | NA | NA | NA |
| bfb74651 | bfb74651 | 50.00 | 0.02 | 0.32 | 1.00 | 26.10 | 22.34 | 18.54 | 11.60 | 16862.20 | 0.12 | 0.29 | 0.39 |
| b6431c50 | b6431c50 | 50.00 | 0.06 | 0.30 | 1.00 | 21.76 | 21.97 | 9.90 | 3.09 | 23196.82 | 0.15 | 0.76 | 0.57 |
| 9fccbd8e | 9fccbd8e | 50.00 | 0.04 | 0.26 | 1.00 | 21.82 | 21.93 | 6.54 | 4.26 | 40887.74 | 0.20 | 0.88 | 0.17 |
| 2528dac0 | 2528dac0 | 50.00 | 0.20 | 0.26 | 1.00 | 28.88 | 25.05 | 12.98 | 7.10 | 27617.72 | 0.24 | 0.78 | 0.51 |
| 1f77af01 | 1f77af01 | 50.00 | 0.00 | 0.26 | 1.00 | 42.72 | 27.88 | 31.10 | 23.75 | 13704.68 | 1.00 | 1.00 | 0.69 |
| dbb2d209 | dbb2d209 | 50.00 | 0.00 | 0.18 | 1.00 | 41.44 | 28.64 | 20.78 | 15.88 | 18154.66 | 0.14 | 0.69 | 0.33 |
| eefdc883 | eefdc883 | 50.00 | 0.02 | 0.16 | 1.00 | 31.00 | 22.35 | 10.72 | 3.40 | 16574.50 | 0.00 | 0.26 | 0.50 |
| 617ae74f | 617ae74f | 50.00 | 0.00 | 0.14 | 1.00 | 29.56 | 21.49 | 15.26 | 9.89 | 19565.26 | 0.16 | 0.40 | 0.50 |
Before we remove outliers, we want a look at how the data stack up (so when we throw away data we know what we’re losing):
From here on down we remove invalid responses and participants who over- and underperformed.
First we drop the 1 participants who didn’t do enough questions.
Next we drop the 0 participants who failed to provide at least 80% sensible answers (of whom 0 probably got ‘after’ and ‘before’ dates the wrong way around).
Having removed those, we then remove the 1 participants with hitrate > 2SD away from the population mean, because they probably looked up the answers (this is not a throwaway; individual answers have been checked and suggest a pattern).
Finally, we remove the 1 participants with a mean bracket width > 2SD away from the population mean because they’re not easily comparable with the others.
With those participants removed, we can provide some general information about performance based on the 30 participants who remain:
| mean | sd | var |
|---|---|---|
| 49.77 | 0.90 | questionCount |
| 0.07 | 0.07 | hitRate |
| 0.45 | 0.17 | bracketRate |
| 1.00 | 0.00 | goodAnswerRate |
| 21.15 | 8.22 | meanError |
| 20.35 | 3.72 | sdError |
| 20.40 | 8.34 | meanBracketWidth |
| 12.98 | 6.47 | sdBracketWidth |
| 25951.68 | 8467.54 | meanRT |
| 0.20 | 0.22 | hard_easy |
| 0.70 | 0.24 | dull_fun |
| 0.43 | 0.14 | tooLong_tooShort |
Having filtered out those who performed suspiciously, those who remain appear to have performed the task properly, getting few questions exactly right, answering almost all questions sensibly, and identifying the correct period approximately half the time.
## Warning: Removed 3 rows containing non-finite values (stat_ydensity).
## Warning: Removed 3 rows containing non-finite values (stat_boxplot).
## Warning: Removed 3 rows containing missing values (geom_point).
## Warning: Removed 1 rows containing non-finite values (stat_smooth).
## Warning: Removed 1 rows containing missing values (geom_point).
## Warning: Removed 1 rows containing non-finite values (stat_smooth).
## Warning: Removed 1 rows containing missing values (geom_point).
Sorted by bracketed %, decreasing.
| qShort | target | topic | n | error.m | error.sd | timeA.m | timeA.sd | bracketed.m | bracketed.sd | bWidth.m | bWidth.sd | hit.m | hit.sd | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| death of Elvis Presl | death of Elvis Presl | 1977.00 | arts | 8.00 | 2.00 | 1.69 | 23327.88 | 9942.66 | 1.00 | 0.00 | 11.88 | 8.66 | 0.25 | 0.46 |
| meltdown at Chernoby | meltdown at Chernoby | 1986.00 | technology | 6.00 | 2.00 | 2.10 | 19325.33 | 3201.82 | 1.00 | 0.00 | 13.67 | 9.48 | 0.17 | 0.41 |
| Harper Lee publishes | Harper Lee publishes | 1960.00 | arts | 8.00 | 8.62 | 7.56 | 17716.75 | 6543.02 | 0.88 | 0.35 | 18.12 | 8.43 | 0.12 | 0.35 |
| John Lennon murdered | John Lennon murdered | 1980.00 | arts | 7.00 | 2.29 | 4.07 | 38340.86 | 37504.11 | 0.86 | 0.38 | 9.29 | 7.06 | 0.71 | 0.49 |
| birth of Queen Eliza | birth of Queen Eliza | 1926.00 | politics | 13.00 | 4.08 | 4.29 | 28756.85 | 10586.82 | 0.85 | 0.38 | 14.00 | 8.62 | 0.08 | 0.28 |
| Margaret Thatcher be | Margaret Thatcher be | 1979.00 | politics | 6.00 | 2.33 | 3.61 | 26726.67 | 16479.96 | 0.83 | 0.41 | 9.67 | 4.59 | 0.50 | 0.55 |
| the Wright brothers | the Wright brothers | 1903.00 | technology | 6.00 | 7.17 | 5.74 | 23768.33 | 14151.53 | 0.83 | 0.41 | 20.17 | 8.38 | 0.00 | 0.00 |
| Neil Armstrong becom | Neil Armstrong becom | 1969.00 | science | 11.00 | 8.64 | 17.73 | 33719.09 | 19096.65 | 0.82 | 0.40 | 15.55 | 25.99 | 0.36 | 0.50 |
| Mike Tyson becomes t | Mike Tyson becomes t | 1986.00 | sport | 11.00 | 4.18 | 4.62 | 34572.64 | 26236.59 | 0.82 | 0.40 | 12.64 | 6.42 | 0.09 | 0.30 |
| assassination of civ | assassination of civ | 1968.00 | politics | 10.00 | 7.60 | 8.29 | 56470.70 | 124802.00 | 0.80 | 0.42 | 14.60 | 7.85 | 0.10 | 0.32 |
| Live Aid concert hel | Live Aid concert hel | 1985.00 | arts | 9.00 | 13.22 | 27.17 | 23451.67 | 14141.40 | 0.78 | 0.44 | 16.00 | 13.57 | 0.22 | 0.44 |
| introduction of the | introduction of the | 1999.00 | politics | 8.00 | 12.00 | 19.52 | 24270.75 | 11185.91 | 0.75 | 0.46 | 14.12 | 24.83 | 0.38 | 0.52 |
| nuclear bombs droppe | nuclear bombs droppe | 1945.00 | military | 8.00 | 10.00 | 16.41 | 24014.50 | 14870.55 | 0.75 | 0.46 | 9.12 | 9.25 | 0.25 | 0.46 |
| 168 people die in th | 168 people die in th | 1995.00 | politics | 8.00 | 29.00 | 33.38 | 45386.12 | 32642.58 | 0.75 | 0.46 | 35.38 | 43.46 | 0.00 | 0.00 |
| first exhibition of | first exhibition of | 1999.00 | arts | 4.00 | 6.50 | 11.68 | 19456.25 | 3261.68 | 0.75 | 0.50 | 9.00 | 8.21 | 0.25 | 0.50 |
| American Food and Dr | American Food and Dr | 1960.00 | politics | 4.00 | 16.00 | 8.98 | 38945.75 | 33402.65 | 0.75 | 0.50 | 30.00 | 16.33 | 0.00 | 0.00 |
| discovery of Tutankh | discovery of Tutankh | 1922.00 | science | 4.00 | 20.75 | 13.43 | 39447.25 | 22901.99 | 0.75 | 0.50 | 46.25 | 38.16 | 0.00 | 0.00 |
| assassination of US | assassination of US | 1963.00 | politics | 15.00 | 7.73 | 12.19 | 23427.80 | 13782.65 | 0.73 | 0.46 | 11.20 | 6.98 | 0.33 | 0.49 |
| the first Mini autom | the first Mini autom | 1959.00 | technology | 11.00 | 17.00 | 19.52 | 32441.82 | 19923.37 | 0.73 | 0.47 | 25.73 | 20.07 | 0.00 | 0.00 |
| Winston Churchill be | Winston Churchill be | 1940.00 | politics | 7.00 | 12.29 | 14.67 | 56614.86 | 53491.36 | 0.71 | 0.49 | 17.57 | 13.82 | 0.14 | 0.38 |
| technology companies | technology companies | 1982.00 | technology | 7.00 | 7.00 | 6.24 | 32666.29 | 28412.07 | 0.71 | 0.49 | 11.86 | 6.12 | 0.00 | 0.00 |
| King George VI dies | King George VI dies | 1952.00 | politics | 7.00 | 18.29 | 28.26 | 29716.86 | 14861.74 | 0.71 | 0.49 | 12.43 | 7.04 | 0.14 | 0.38 |
| Germaine Greer publi | Germaine Greer publi | 1970.00 | politics | 7.00 | 11.14 | 10.82 | 25130.57 | 19120.29 | 0.71 | 0.49 | 17.29 | 18.90 | 0.29 | 0.49 |
| break-in at the Demo | break-in at the Demo | 1972.00 | politics | 7.00 | 17.43 | 29.00 | 28278.00 | 10519.02 | 0.71 | 0.49 | 18.71 | 13.96 | 0.00 | 0.00 |
| creation of the Nort | creation of the Nort | 1949.00 | military | 10.00 | 7.00 | 9.91 | 20245.90 | 7522.94 | 0.70 | 0.48 | 20.30 | 16.92 | 0.20 | 0.42 |
| launch of the Hubble | launch of the Hubble | 1990.00 | science | 10.00 | 10.20 | 12.35 | 22911.60 | 10612.08 | 0.70 | 0.48 | 14.90 | 7.17 | 0.20 | 0.42 |
| Chinese invasion of | Chinese invasion of | 1950.00 | military | 10.00 | 18.20 | 18.75 | 23268.30 | 10872.80 | 0.70 | 0.48 | 25.30 | 21.15 | 0.20 | 0.42 |
| Sean Connery plays J | Sean Connery plays J | 1962.00 | arts | 10.00 | 9.80 | 9.57 | 21320.00 | 10349.38 | 0.70 | 0.48 | 17.40 | 8.49 | 0.00 | 0.00 |
| first episode of Who | first episode of Who | 1998.00 | arts | 12.00 | 9.67 | 10.78 | 24816.33 | 13980.63 | 0.67 | 0.49 | 13.00 | 12.72 | 0.17 | 0.39 |
| capture and executio | capture and executio | 1967.00 | politics | 9.00 | 12.89 | 22.78 | 24436.56 | 7039.97 | 0.67 | 0.50 | 18.11 | 10.75 | 0.11 | 0.33 |
| World War I Armistic | World War I Armistic | 1918.00 | military | 9.00 | 9.00 | 21.82 | 26366.78 | 11758.90 | 0.67 | 0.50 | 6.33 | 5.61 | 0.33 | 0.50 |
| Soviet cosmonaut Yur | Soviet cosmonaut Yur | 1961.00 | science | 9.00 | 8.33 | 10.98 | 25532.44 | 9790.85 | 0.67 | 0.50 | 17.67 | 12.96 | 0.11 | 0.33 |
| Austrian bodybuilder | Austrian bodybuilder | 1965.00 | sport | 9.00 | 9.00 | 7.83 | 22215.44 | 10506.17 | 0.67 | 0.50 | 19.56 | 10.63 | 0.11 | 0.33 |
| successful mammalian | successful mammalian | 1996.00 | science | 6.00 | 8.17 | 5.78 | 21635.50 | 11164.68 | 0.67 | 0.52 | 14.67 | 4.50 | 0.00 | 0.00 |
| musical Cats opens i | musical Cats opens i | 1981.00 | arts | 3.00 | 6.33 | 4.51 | 21370.67 | 14088.54 | 0.67 | 0.58 | 13.33 | 5.77 | 0.00 | 0.00 |
| the Soviet Union is | the Soviet Union is | 1991.00 | politics | 11.00 | 13.82 | 25.00 | 26526.45 | 11921.42 | 0.64 | 0.50 | 14.18 | 18.91 | 0.18 | 0.40 |
| actress Marilyn Munr | actress Marilyn Munr | 1962.00 | arts | 11.00 | 8.64 | 9.95 | 29565.18 | 17175.71 | 0.64 | 0.50 | 15.64 | 12.31 | 0.18 | 0.40 |
| apartheid begins in | apartheid begins in | 1948.00 | politics | 8.00 | 15.00 | 14.24 | 23521.88 | 13984.57 | 0.62 | 0.52 | 42.38 | 30.65 | 0.00 | 0.00 |
| Diana, Princess of W | Diana, Princess of W | 1997.00 | politics | 8.00 | 11.75 | 21.10 | 25341.62 | 18359.57 | 0.62 | 0.52 | 14.25 | 13.33 | 0.12 | 0.35 |
| the Arab Revolt begi | the Arab Revolt begi | 1916.00 | military | 8.00 | 20.12 | 18.00 | 17994.38 | 4648.98 | 0.62 | 0.52 | 26.25 | 13.02 | 0.00 | 0.00 |
| Monty Python’s Flyin | Monty Python’s Flyin | 1969.00 | arts | 8.00 | 8.00 | 6.61 | 28864.00 | 16252.22 | 0.62 | 0.52 | 18.38 | 12.64 | 0.00 | 0.00 |
| US-led coalition exp | US-led coalition exp | 1991.00 | military | 10.00 | 18.10 | 28.69 | 28247.70 | 19255.19 | 0.60 | 0.52 | 17.40 | 14.34 | 0.00 | 0.00 |
| ’Father of Psycholog | ’Father of Psycholog | 1910.00 | science | 10.00 | 26.40 | 23.09 | 23618.30 | 9508.69 | 0.60 | 0.52 | 26.30 | 18.32 | 0.00 | 0.00 |
| penicillin discovere | penicillin discovere | 1928.00 | science | 10.00 | 15.10 | 11.14 | 25630.40 | 12498.55 | 0.60 | 0.52 | 26.60 | 11.79 | 0.00 | 0.00 |
| the Wall Street cras | the Wall Street cras | 1929.00 | politics | 10.00 | 16.00 | 19.66 | 20392.30 | 9721.46 | 0.60 | 0.52 | 13.50 | 7.79 | 0.40 | 0.52 |
| Space Shuttle Challe | Space Shuttle Challe | 1986.00 | technology | 10.00 | 7.40 | 7.37 | 28848.30 | 17893.54 | 0.60 | 0.52 | 13.50 | 10.41 | 0.10 | 0.32 |
| Woodstock Music Fest | Woodstock Music Fest | 1969.00 | arts | 12.00 | 9.33 | 10.41 | 23064.50 | 15271.23 | 0.58 | 0.51 | 12.75 | 9.09 | 0.17 | 0.39 |
| US poet Sylvia Plath | US poet Sylvia Plath | 1963.00 | arts | 14.00 | 18.50 | 16.36 | 21996.86 | 9918.70 | 0.57 | 0.51 | 32.07 | 33.32 | 0.07 | 0.27 |
| Benito Mussolini fou | Benito Mussolini fou | 1921.00 | politics | 7.00 | 18.00 | 26.40 | 18967.00 | 9465.56 | 0.57 | 0.53 | 24.14 | 13.57 | 0.00 | 0.00 |
| Emily Wilding Daviso | Emily Wilding Daviso | 1913.00 | politics | 7.00 | 27.14 | 29.45 | 23342.14 | 14353.18 | 0.57 | 0.53 | 22.00 | 11.60 | 0.14 | 0.38 |
| the teddy bear is in | the teddy bear is in | 1903.00 | technology | 7.00 | 38.57 | 31.71 | 18817.43 | 12244.27 | 0.57 | 0.53 | 32.14 | 31.34 | 0.00 | 0.00 |
| October Revolution i | October Revolution i | 1917.00 | politics | 7.00 | 22.14 | 26.39 | 19999.86 | 7260.70 | 0.57 | 0.53 | 17.71 | 27.91 | 0.29 | 0.49 |
| Salman Rushdie publi | Salman Rushdie publi | 1988.00 | arts | 9.00 | 30.11 | 32.72 | 19171.33 | 10451.94 | 0.56 | 0.53 | 18.22 | 7.26 | 0.00 | 0.00 |
| RMS Titanic begins h | RMS Titanic begins h | 1912.00 | technology | 11.00 | 14.09 | 24.36 | 17462.73 | 7547.38 | 0.55 | 0.52 | 14.45 | 15.12 | 0.36 | 0.50 |
| first FIFA World Cup | first FIFA World Cup | 1930.00 | sport | 13.00 | 13.62 | 13.43 | 27257.85 | 14175.95 | 0.54 | 0.52 | 22.77 | 13.01 | 0.15 | 0.38 |
| Ireland achieves ind | Ireland achieves ind | 1922.00 | military | 14.00 | 22.86 | 20.56 | 20833.43 | 9411.63 | 0.50 | 0.52 | 28.14 | 23.63 | 0.00 | 0.00 |
| dissolution of the u | dissolution of the u | 1905.00 | politics | 12.00 | 35.08 | 30.43 | 21001.67 | 11501.18 | 0.50 | 0.52 | 33.25 | 23.83 | 0.00 | 0.00 |
| foundation of Disney | foundation of Disney | 1923.00 | technology | 12.00 | 16.50 | 19.36 | 35493.67 | 51296.11 | 0.50 | 0.52 | 19.75 | 11.71 | 0.08 | 0.29 |
| initiation of the Ma | initiation of the Ma | 1942.00 | science | 10.00 | 24.60 | 19.22 | 18739.40 | 7539.85 | 0.50 | 0.53 | 22.80 | 13.45 | 0.00 | 0.00 |
| artist Frida Kahlo b | artist Frida Kahlo b | 1907.00 | arts | 10.00 | 14.80 | 15.75 | 26428.30 | 13551.55 | 0.50 | 0.53 | 24.20 | 12.55 | 0.00 | 0.00 |
| partition of India i | partition of India i | 1947.00 | politics | 10.00 | 14.70 | 13.77 | 33460.90 | 25146.52 | 0.50 | 0.53 | 24.00 | 20.25 | 0.00 | 0.00 |
| Egypt invaded by Isr | Egypt invaded by Isr | 1956.00 | military | 10.00 | 12.30 | 8.45 | 24728.60 | 11631.17 | 0.50 | 0.53 | 19.90 | 11.51 | 0.10 | 0.32 |
| Mao Zedong establish | Mao Zedong establish | 1949.00 | politics | 8.00 | 14.75 | 16.95 | 23050.75 | 9667.30 | 0.50 | 0.53 | 32.00 | 33.42 | 0.12 | 0.35 |
| up to 1 million peop | up to 1 million peop | 1994.00 | military | 8.00 | 33.62 | 30.39 | 29983.12 | 20938.35 | 0.50 | 0.53 | 28.12 | 33.80 | 0.00 | 0.00 |
| W.B. Yeats awarded t | W.B. Yeats awarded t | 1923.00 | arts | 8.00 | 27.00 | 25.12 | 24913.88 | 18975.70 | 0.50 | 0.53 | 34.88 | 22.81 | 0.00 | 0.00 |
| Virginia Wolfe publi | Virginia Wolfe publi | 1925.00 | arts | 8.00 | 26.12 | 26.59 | 17658.25 | 17083.37 | 0.50 | 0.53 | 18.00 | 7.69 | 0.00 | 0.00 |
| Triangle Shirtwaist | Triangle Shirtwaist | 1911.00 | politics | 8.00 | 18.25 | 23.66 | 19093.75 | 9115.40 | 0.50 | 0.53 | 17.50 | 15.59 | 0.00 | 0.00 |
| Port Arthur, Canada | Port Arthur, Canada | 1908.00 | politics | 8.00 | 32.50 | 28.75 | 20324.50 | 8951.40 | 0.50 | 0.53 | 20.62 | 13.31 | 0.12 | 0.35 |
| Maya Angelou publish | Maya Angelou publish | 1969.00 | arts | 8.00 | 17.38 | 17.41 | 24835.25 | 17833.32 | 0.50 | 0.53 | 27.50 | 12.54 | 0.00 | 0.00 |
| the Russian Social D | the Russian Social D | 1903.00 | politics | 6.00 | 18.33 | 12.48 | 22682.83 | 15610.21 | 0.50 | 0.55 | 25.83 | 19.25 | 0.00 | 0.00 |
| maiden flight of Con | maiden flight of Con | 1969.00 | technology | 6.00 | 8.50 | 9.48 | 27046.83 | 17347.63 | 0.50 | 0.55 | 10.83 | 5.85 | 0.33 | 0.52 |
| Japanese invasion of | Japanese invasion of | 1937.00 | military | 6.00 | 11.33 | 9.48 | 24290.00 | 13727.92 | 0.50 | 0.55 | 17.83 | 10.40 | 0.00 | 0.00 |
| Frigidaire begins se | Frigidaire begins se | 1923.00 | technology | 6.00 | 10.00 | 7.80 | 28900.67 | 20581.46 | 0.50 | 0.55 | 26.67 | 13.66 | 0.00 | 0.00 |
| Steven Spielberg dir | Steven Spielberg dir | 1993.00 | arts | 6.00 | 5.17 | 4.36 | 20349.50 | 8958.97 | 0.50 | 0.55 | 12.83 | 5.71 | 0.17 | 0.41 |
| Israel established a | Israel established a | 1948.00 | politics | 4.00 | 11.25 | 7.80 | 44767.25 | 24211.13 | 0.50 | 0.58 | 19.25 | 15.78 | 0.00 | 0.00 |
| Britain and Argentin | Britain and Argentin | 1982.00 | military | 4.00 | 29.25 | 39.38 | 28828.00 | 8246.92 | 0.50 | 0.58 | 23.00 | 24.99 | 0.00 | 0.00 |
| Saigon (now Ho Chi M | Saigon (now Ho Chi M | 1975.00 | military | 11.00 | 13.27 | 12.43 | 28827.73 | 9025.00 | 0.45 | 0.52 | 18.91 | 18.07 | 0.09 | 0.30 |
| Civil Rights Act out | Civil Rights Act out | 1964.00 | politics | 11.00 | 19.27 | 22.09 | 16225.36 | 5573.65 | 0.45 | 0.52 | 14.55 | 8.34 | 0.00 | 0.00 |
| Human Immunodeficien | Human Immunodeficien | 1983.00 | science | 11.00 | 11.73 | 17.50 | 18762.73 | 6244.93 | 0.45 | 0.52 | 14.55 | 7.34 | 0.00 | 0.00 |
| RMS Lusitania sunk b | RMS Lusitania sunk b | 1915.00 | military | 11.00 | 20.64 | 17.96 | 30384.09 | 16615.79 | 0.45 | 0.52 | 13.27 | 13.32 | 0.09 | 0.30 |
| James Joyce’s Ulysse | James Joyce’s Ulysse | 1922.00 | arts | 11.00 | 29.18 | 25.38 | 18761.45 | 8936.86 | 0.45 | 0.52 | 38.91 | 33.12 | 0.00 | 0.00 |
| King George VI gives | King George VI gives | 1932.00 | politics | 9.00 | 18.44 | 14.88 | 22233.00 | 7454.26 | 0.44 | 0.53 | 25.00 | 16.20 | 0.00 | 0.00 |
| Tunguska event flatt | Tunguska event flatt | 1908.00 | science | 9.00 | 39.11 | 32.79 | 21755.00 | 17751.35 | 0.44 | 0.53 | 34.44 | 23.38 | 0.00 | 0.00 |
| public prosecution o | public prosecution o | 1960.00 | arts | 9.00 | 17.67 | 17.90 | 21781.33 | 10537.29 | 0.44 | 0.53 | 24.89 | 16.47 | 0.22 | 0.44 |
| riots in Los Angeles | riots in Los Angeles | 1992.00 | politics | 9.00 | 18.78 | 23.06 | 36056.67 | 15747.25 | 0.44 | 0.53 | 11.33 | 14.83 | 0.00 | 0.00 |
| synthetic polymer ny | synthetic polymer ny | 1938.00 | technology | 16.00 | 22.94 | 17.85 | 22127.44 | 13742.32 | 0.44 | 0.51 | 26.62 | 17.64 | 0.00 | 0.00 |
| the Turkish Republic | the Turkish Republic | 1924.00 | politics | 7.00 | 27.57 | 24.95 | 19951.71 | 13501.45 | 0.43 | 0.53 | 32.86 | 18.68 | 0.00 | 0.00 |
| Pluto discovered by | Pluto discovered by | 1930.00 | science | 7.00 | 18.86 | 19.94 | 16146.43 | 5634.75 | 0.43 | 0.53 | 36.43 | 33.75 | 0.14 | 0.38 |
| Cuban Missile Crisis | Cuban Missile Crisis | 1962.00 | military | 7.00 | 20.57 | 27.51 | 38089.86 | 44743.06 | 0.43 | 0.53 | 14.43 | 12.09 | 0.29 | 0.49 |
| Joseph Stalin’s Grea | Joseph Stalin’s Grea | 1936.00 | politics | 7.00 | 10.71 | 7.23 | 26654.00 | 11275.10 | 0.43 | 0.53 | 15.00 | 7.81 | 0.00 | 0.00 |
| opening of the Chann | opening of the Chann | 1994.00 | technology | 7.00 | 20.00 | 21.60 | 19278.43 | 13544.04 | 0.43 | 0.53 | 16.57 | 9.25 | 0.14 | 0.38 |
| end of British rule | end of British rule | 1997.00 | politics | 12.00 | 29.17 | 29.08 | 23527.50 | 15567.23 | 0.42 | 0.51 | 18.08 | 14.63 | 0.17 | 0.39 |
| Spanish Civil War be | Spanish Civil War be | 1936.00 | military | 15.00 | 20.60 | 15.45 | 18428.47 | 7793.14 | 0.40 | 0.51 | 24.00 | 16.12 | 0.13 | 0.35 |
| Steffi Graf becomes | Steffi Graf becomes | 1987.00 | sport | 10.00 | 13.30 | 8.50 | 32917.00 | 22494.92 | 0.40 | 0.52 | 17.40 | 12.64 | 0.00 | 0.00 |
| ballet dancer Mikhai | ballet dancer Mikhai | 1974.00 | arts | 10.00 | 14.90 | 14.92 | 22253.90 | 8062.22 | 0.40 | 0.52 | 18.00 | 15.13 | 0.00 | 0.00 |
| the zeppelin Hindenb | the zeppelin Hindenb | 1937.00 | technology | 10.00 | 15.50 | 8.55 | 23408.10 | 5960.88 | 0.40 | 0.52 | 21.20 | 8.70 | 0.00 | 0.00 |
| Orson Welles’ Citize | Orson Welles’ Citize | 1941.00 | arts | 5.00 | 17.40 | 19.71 | 33136.20 | 16876.47 | 0.40 | 0.55 | 22.40 | 14.10 | 0.00 | 0.00 |
| first moving assembl | first moving assembl | 1913.00 | technology | 5.00 | 20.60 | 25.74 | 17799.80 | 8887.11 | 0.40 | 0.55 | 16.00 | 5.48 | 0.20 | 0.45 |
| first Disneyland ope | first Disneyland ope | 1955.00 | technology | 5.00 | 15.40 | 10.53 | 47075.80 | 47249.61 | 0.40 | 0.55 | 16.60 | 18.84 | 0.00 | 0.00 |
| first link establish | first link establish | 1969.00 | technology | 8.00 | 11.12 | 6.77 | 22739.50 | 12510.60 | 0.38 | 0.52 | 23.38 | 12.18 | 0.00 | 0.00 |
| Edmund Hillary and T | Edmund Hillary and T | 1953.00 | sport | 8.00 | 18.12 | 11.15 | 27264.50 | 12464.19 | 0.38 | 0.52 | 23.88 | 13.39 | 0.00 | 0.00 |
| Charles de Gaulle el | Charles de Gaulle el | 1958.00 | politics | 8.00 | 18.00 | 12.80 | 20250.62 | 8342.88 | 0.38 | 0.52 | 20.62 | 18.86 | 0.00 | 0.00 |
| foundation of the Mu | foundation of the Mu | 1928.00 | politics | 8.00 | 30.75 | 25.68 | 30809.62 | 18596.88 | 0.38 | 0.52 | 24.38 | 20.08 | 0.12 | 0.35 |
| birth of Louise Brow | birth of Louise Brow | 1978.00 | technology | 8.00 | 11.75 | 15.24 | 30518.12 | 22542.03 | 0.38 | 0.52 | 20.00 | 14.88 | 0.00 | 0.00 |
| death of Martha, the | death of Martha, the | 1914.00 | science | 8.00 | 28.12 | 29.63 | 37954.38 | 20118.62 | 0.38 | 0.52 | 22.50 | 14.88 | 0.12 | 0.35 |
| Mahatma Gandhi’s fir | Mahatma Gandhi’s fir | 1920.00 | politics | 11.00 | 39.82 | 19.15 | 31201.55 | 24792.56 | 0.36 | 0.50 | 33.00 | 20.66 | 0.00 | 0.00 |
| creation of the Cent | creation of the Cent | 1947.00 | politics | 11.00 | 15.64 | 15.60 | 16818.73 | 6301.26 | 0.36 | 0.50 | 18.91 | 10.24 | 0.00 | 0.00 |
| Britain replaces pou | Britain replaces pou | 1971.00 | technology | 12.00 | 20.75 | 18.31 | 25479.50 | 18460.96 | 0.33 | 0.49 | 15.67 | 4.12 | 0.00 | 0.00 |
| high school teacher | high school teacher | 1925.00 | politics | 12.00 | 33.92 | 20.32 | 25329.00 | 17473.21 | 0.33 | 0.49 | 24.50 | 14.02 | 0.00 | 0.00 |
| Guglielmo Marconi re | Guglielmo Marconi re | 1901.00 | technology | 9.00 | 16.56 | 14.96 | 20742.00 | 9015.52 | 0.33 | 0.50 | 23.89 | 16.35 | 0.11 | 0.33 |
| premier of John Cage | premier of John Cage | 1952.00 | arts | 9.00 | 26.44 | 15.16 | 26359.89 | 23871.34 | 0.33 | 0.50 | 23.44 | 29.61 | 0.00 | 0.00 |
| the Chinese Empire e | the Chinese Empire e | 1912.00 | politics | 9.00 | 22.78 | 14.54 | 28900.67 | 17147.89 | 0.33 | 0.50 | 21.11 | 15.96 | 0.11 | 0.33 |
| Steve Jobs and Steve | Steve Jobs and Steve | 1976.00 | technology | 9.00 | 9.11 | 6.86 | 25071.89 | 16581.29 | 0.33 | 0.50 | 13.44 | 10.15 | 0.00 | 0.00 |
| Germany enacts the N | Germany enacts the N | 1935.00 | politics | 9.00 | 19.56 | 16.87 | 30779.33 | 28730.89 | 0.33 | 0.50 | 16.44 | 13.13 | 0.00 | 0.00 |
| George Orwell publis | George Orwell publis | 1949.00 | arts | 9.00 | 14.11 | 7.99 | 25695.44 | 12433.28 | 0.33 | 0.50 | 22.89 | 11.10 | 0.00 | 0.00 |
| US Supreme Court rul | US Supreme Court rul | 1973.00 | politics | 9.00 | 15.33 | 12.22 | 24111.33 | 15139.28 | 0.33 | 0.50 | 24.67 | 27.19 | 0.00 | 0.00 |
| Panama Canal opens | Panama Canal opens | 1914.00 | technology | 6.00 | 36.50 | 27.49 | 13402.67 | 5689.07 | 0.33 | 0.52 | 26.67 | 19.66 | 0.00 | 0.00 |
| George Nissen and La | George Nissen and La | 1936.00 | sport | 6.00 | 29.17 | 16.29 | 15946.17 | 7068.56 | 0.33 | 0.52 | 30.00 | 16.43 | 0.00 | 0.00 |
| prohibition abolishe | prohibition abolishe | 1933.00 | politics | 6.00 | 21.17 | 18.90 | 14489.67 | 3952.28 | 0.33 | 0.52 | 18.83 | 8.84 | 0.17 | 0.41 |
| George Gershwin’s Rh | George Gershwin’s Rh | 1924.00 | arts | 6.00 | 25.50 | 15.19 | 21411.83 | 7385.21 | 0.33 | 0.52 | 23.00 | 10.26 | 0.00 | 0.00 |
| J.D. Salinger publis | J.D. Salinger publis | 1951.00 | arts | 6.00 | 19.33 | 8.41 | 20190.00 | 11888.07 | 0.33 | 0.52 | 20.83 | 14.97 | 0.00 | 0.00 |
| first The Wizard of | first The Wizard of | 1902.00 | arts | 6.00 | 32.33 | 33.48 | 20012.33 | 11776.17 | 0.33 | 0.52 | 17.50 | 6.12 | 0.00 | 0.00 |
| the Flying Scotsman | the Flying Scotsman | 1934.00 | technology | 6.00 | 20.67 | 10.88 | 28329.50 | 13322.07 | 0.33 | 0.52 | 28.33 | 21.13 | 0.00 | 0.00 |
| Igor Stravinsky’s ba | Igor Stravinsky’s ba | 1913.00 | arts | 13.00 | 38.62 | 27.02 | 19372.62 | 8118.65 | 0.31 | 0.48 | 21.77 | 9.20 | 0.00 | 0.00 |
| Roger Bannister runs | Roger Bannister runs | 1954.00 | sport | 10.00 | 16.50 | 14.68 | 29969.30 | 24297.83 | 0.30 | 0.48 | 15.10 | 8.03 | 0.00 | 0.00 |
| sisters Laura Richar | sisters Laura Richar | 1917.00 | arts | 10.00 | 40.70 | 25.05 | 19776.50 | 11631.88 | 0.30 | 0.48 | 26.30 | 9.72 | 0.00 | 0.00 |
| first Tour de France | first Tour de France | 1903.00 | sport | 10.00 | 53.60 | 32.15 | 19943.90 | 7235.37 | 0.30 | 0.48 | 21.00 | 21.69 | 0.00 | 0.00 |
| draughtsman Harry Be | draughtsman Harry Be | 1931.00 | technology | 14.00 | 29.21 | 20.73 | 24705.86 | 15623.77 | 0.29 | 0.47 | 25.57 | 11.81 | 0.00 | 0.00 |
| British Commonwealth | British Commonwealth | 1931.00 | politics | 7.00 | 29.00 | 15.35 | 18407.43 | 7205.13 | 0.29 | 0.49 | 30.71 | 31.01 | 0.00 | 0.00 |
| Albert Einstein publ | Albert Einstein publ | 1905.00 | science | 7.00 | 29.43 | 24.85 | 36148.86 | 32358.56 | 0.29 | 0.49 | 19.29 | 12.72 | 0.00 | 0.00 |
| Douglas Adams’ The H | Douglas Adams’ The H | 1978.00 | arts | 7.00 | 13.86 | 11.96 | 27420.00 | 25147.60 | 0.29 | 0.49 | 16.29 | 11.10 | 0.00 | 0.00 |
| Andrew Wiles publish | Andrew Wiles publish | 1995.00 | science | 7.00 | 54.00 | 36.38 | 23956.43 | 15418.75 | 0.29 | 0.49 | 51.57 | 35.77 | 0.00 | 0.00 |
| the Bureau of Invest | the Bureau of Invest | 1908.00 | politics | 11.00 | 36.73 | 33.86 | 28207.82 | 17644.06 | 0.27 | 0.47 | 18.09 | 12.16 | 0.00 | 0.00 |
| Eugene Burton Ely pe | Eugene Burton Ely pe | 1911.00 | technology | 11.00 | 39.27 | 29.69 | 21075.82 | 8688.67 | 0.27 | 0.47 | 21.45 | 15.27 | 0.00 | 0.00 |
| the Federal Reserve | the Federal Reserve | 1913.00 | politics | 11.00 | 32.09 | 26.69 | 34464.27 | 21769.01 | 0.27 | 0.47 | 20.82 | 13.20 | 0.00 | 0.00 |
| World Health Organis | World Health Organis | 1948.00 | politics | 11.00 | 20.36 | 13.77 | 16167.18 | 9878.54 | 0.27 | 0.47 | 13.82 | 6.11 | 0.09 | 0.30 |
| thousands of protest | thousands of protest | 1989.00 | politics | 8.00 | 34.00 | 16.69 | 16004.75 | 7005.03 | 0.25 | 0.46 | 20.62 | 8.63 | 0.00 | 0.00 |
| murder of Russian my | murder of Russian my | 1916.00 | politics | 8.00 | 39.50 | 32.13 | 21243.62 | 14103.49 | 0.25 | 0.46 | 21.88 | 14.14 | 0.00 | 0.00 |
| oldest known cave pa | oldest known cave pa | 1994.00 | arts | 13.00 | 48.92 | 30.08 | 27445.31 | 18496.55 | 0.23 | 0.44 | 30.08 | 21.52 | 0.00 | 0.00 |
| Emily Hobhouse deliv | Emily Hobhouse deliv | 1901.00 | politics | 9.00 | 37.56 | 34.85 | 29518.22 | 17263.99 | 0.22 | 0.44 | 18.56 | 12.40 | 0.00 | 0.00 |
| Roald Amundsen reach | Roald Amundsen reach | 1911.00 | science | 9.00 | 25.67 | 28.54 | 27974.44 | 19716.99 | 0.22 | 0.44 | 18.00 | 10.27 | 0.22 | 0.44 |
| Willis Carrier inven | Willis Carrier inven | 1902.00 | technology | 9.00 | 41.00 | 25.32 | 32225.00 | 21424.21 | 0.22 | 0.44 | 20.78 | 12.89 | 0.00 | 0.00 |
| Tim Berners-Lee publ | Tim Berners-Lee publ | 1991.00 | technology | 9.00 | 8.56 | 5.66 | 35437.78 | 42295.27 | 0.22 | 0.44 | 11.89 | 7.61 | 0.00 | 0.00 |
| The USA officially a | The USA officially a | 1931.00 | arts | 10.00 | 21.50 | 18.67 | 56028.30 | 92391.79 | 0.20 | 0.42 | 23.90 | 16.80 | 0.00 | 0.00 |
| last two judicial ex | last two judicial ex | 1964.00 | politics | 10.00 | 29.00 | 24.17 | 25790.60 | 11581.32 | 0.20 | 0.42 | 23.30 | 10.25 | 0.00 | 0.00 |
| the Velvet Revolutio | the Velvet Revolutio | 1989.00 | politics | 5.00 | 39.00 | 38.94 | 28506.40 | 13881.33 | 0.20 | 0.45 | 30.20 | 19.31 | 0.00 | 0.00 |
| Augusto Pinochet beg | Augusto Pinochet beg | 1973.00 | politics | 5.00 | 17.40 | 9.66 | 22554.80 | 8830.86 | 0.20 | 0.45 | 12.40 | 4.51 | 0.00 | 0.00 |
| Janet Gaynor wins ’B | Janet Gaynor wins ’B | 1929.00 | arts | 11.00 | 31.36 | 18.73 | 15772.09 | 6417.67 | 0.18 | 0.40 | 25.00 | 9.22 | 0.00 | 0.00 |
| Jack Kerouac publish | Jack Kerouac publish | 1957.00 | arts | 11.00 | 21.91 | 12.19 | 14203.55 | 8083.20 | 0.18 | 0.40 | 18.18 | 8.45 | 0.00 | 0.00 |
| the Hoover Dam is co | the Hoover Dam is co | 1936.00 | technology | 11.00 | 17.82 | 12.70 | 28138.64 | 42378.31 | 0.18 | 0.40 | 19.27 | 13.22 | 0.00 | 0.00 |
| Charlie Chaplin’s Th | Charlie Chaplin’s Th | 1940.00 | arts | 6.00 | 20.50 | 13.32 | 16870.33 | 10235.75 | 0.17 | 0.41 | 17.33 | 2.94 | 0.00 | 0.00 |
| Nancy Astor, Viscoun | Nancy Astor, Viscoun | 1919.00 | politics | 6.00 | 32.33 | 22.51 | 18004.50 | 4025.25 | 0.17 | 0.41 | 15.00 | 8.94 | 0.00 | 0.00 |
| Colossus, the first | Colossus, the first | 1944.00 | technology | 6.00 | 21.00 | 14.83 | 21577.50 | 10527.89 | 0.17 | 0.41 | 17.17 | 15.14 | 0.00 | 0.00 |
| Stonewall riots in N | Stonewall riots in N | 1969.00 | politics | 7.00 | 15.43 | 10.28 | 22890.86 | 14471.67 | 0.14 | 0.38 | 17.43 | 7.61 | 0.00 | 0.00 |
| first photograph of | first photograph of | 1946.00 | technology | 8.00 | 20.62 | 9.96 | 22846.00 | 9385.50 | 0.12 | 0.35 | 19.75 | 9.48 | 0.00 | 0.00 |
| Thalidomide is withd | Thalidomide is withd | 1961.00 | science | 9.00 | 24.56 | 20.38 | 24967.67 | 18703.17 | 0.11 | 0.33 | 17.22 | 15.63 | 0.00 | 0.00 |
| first photographs of | first photographs of | 1910.00 | science | 9.00 | 50.67 | 29.58 | 21421.00 | 13542.52 | 0.11 | 0.33 | 14.00 | 8.89 | 0.00 | 0.00 |
| Estonia wins indepen | Estonia wins indepen | 1920.00 | military | 11.00 | 58.00 | 20.92 | 38600.82 | 48608.79 | 0.09 | 0.30 | 16.09 | 9.53 | 0.00 | 0.00 |
| Chuck Yeager officia | Chuck Yeager officia | 1947.00 | technology | 12.00 | 29.50 | 11.48 | 23610.75 | 12360.92 | 0.08 | 0.29 | 17.00 | 11.03 | 0.00 | 0.00 |
| inaugural elections | inaugural elections | 1906.00 | politics | 10.00 | 50.70 | 27.04 | 25631.50 | 16409.99 | 0.00 | 0.00 | 20.70 | 10.92 | 0.00 | 0.00 |
| Simone de Beauvoir p | Simone de Beauvoir p | 1949.00 | arts | 9.00 | 29.00 | 11.58 | 16411.33 | 6963.07 | 0.00 | 0.00 | 19.22 | 15.13 | 0.00 | 0.00 |
| Henry Dunant, founde | Henry Dunant, founde | 1901.00 | politics | 8.00 | 48.25 | 28.18 | 22094.88 | 16081.14 | 0.00 | 0.00 | 21.25 | 13.82 | 0.00 | 0.00 |
| foundation of the So | foundation of the So | 1912.00 | politics | 6.00 | 47.00 | 19.92 | 35760.00 | 24227.27 | 0.00 | 0.00 | 20.83 | 20.10 | 0.00 | 0.00 |
| 144 people die in Ab | 144 people die in Ab | 1966.00 | politics | 5.00 | 34.60 | 18.37 | 27803.00 | 12826.78 | 0.00 | 0.00 | 15.40 | 4.56 | 0.00 | 0.00 |
| the Lateran Treaty e | the Lateran Treaty e | 1929.00 | politics | 5.00 | 28.20 | 5.22 | 28090.80 | 26955.16 | 0.00 | 0.00 | 14.40 | 16.33 | 0.00 | 0.00 |
| creation of the Brit | creation of the Brit | 1927.00 | politics | 4.00 | 41.75 | 24.51 | 13013.25 | 6962.02 | 0.00 | 0.00 | 15.00 | 5.77 | 0.00 | 0.00 |
(This might look better rotated through 90 degrees)
We examine item performance in terms of response accuracy (hitrate), response times, bracketing rates (i.e. the proportion of participants for whom the event occurs between their ‘after’ and ‘before’ dates), and bracket widths (i.e. the distance between their ‘after’ and ‘before’ dates).
The intuitions about these measures are as follows:
accuracy
a high hit rate suggests that the answer is quite obvious; many participants ‘just know’ the answer
bracketing widths on questions with high hit rates, and which a participant gets correct, may be indicative of a base level of confidence
response times
short response times can suggest extremes; either participants find the question very easy, or they know rapidly that they cannot sensibly guess at the answer
long response times and high accuracy may indicate looking up the answers
bracketing rates
high bracketing rates indicate participants have a good sense of the general period in which something happened
most usefully interpreted in conjunction with bracket widths
bracket widths
narrow bracket widths suggest that the period in which a date might occur is well known.
in isolation, bracket widths are the best indicator of the difficulty of a question
Combining these, the best questions will have moderate response times and bracket widths, will have high bracketing rates, and will have accuracy rates which are not too high.
We can aim for something like:
~the true answer should be closer to the mean estimate than either the mean after or mean before date~
<= 33% accuracy
>= 33% bracket rate
bracket widths and response times in the middle 50% of responses
## Warning in DE$qPrompt == DE.qs$q: longer object length is not a multiple of
## shorter object length
## Warning in DE$qPrompt == DE.qs$q: longer object length is not a multiple of
## shorter object length
## Warning in DE$qPrompt == DE.qs$q: longer object length is not a multiple of
## shorter object length
| Var1 | Freq |
|---|---|
| largeBracket | 2 |
| smallBracket | 5 |
| TRUE | 159 |